Furnace for heat treatment of armor-piercing projectiles



F. C. LNGENBERG AND I. F. FETTERLY. FURNACE FOR HEAT TREATMENT- 0F ARMOR PIERCING RROIECTILES.

APPLICATION FILED DEC. I8, 1919.

Patented Nv. 16, 1920.

4 SHEETS-SHEET I.

F. C.' LANGENBERG AND J. F. FETTERLY. v FURNACE FORv HEAT TREATMENT 0F ARMOR PIERCING PROJECTILES. APPLlcATloN man ntc.1s.i919.

Patented Nov. 16, 1920. l 4 SHEETS-SHEET 2.

F. C. LANGENBERG-AND J. `F. FETTERLY.

FURNACE FOR HEAT TREATMENT 0F ARMOR PIERCING PROIECTILES.

l APPLICATION FILED DEC. I8. 1919.

Patented Nov. 16, 1920.

4 SHEETS-SHEET 3.

' F. C. LANGENBEHG AND J. F. FETTERLY.

FURNACE FOR HEAT TREATMENT 0F ARMOR PIERCING PHOJECTILES.

l APPLICATION FlLED DEC. I8', 1919.

4 SHEETS-SHEET 4.

1,358,755.` Pamauov; 16,1920.

UNITED sTArgs 'PATENT OFFICE.

REDERICK C. LANGENBERG, 0F CAMBRIDGE, MASSACHUSETTS, AND

FETTERLY, OF ALTOONA, PENNSYLVANIA.

JOI-IN F.

FURCN'ACE FOR HEAT'TREATMENT l0F ARMOR-PIERCING PROJECTILES.

Application led December 18, 1919.

Specification of Letters Patent.

Patented N ov. 16, 1920.

Serial No. 345,867.

(FILED IINDER THE'ACT 0F MARCH 3, 1883, 22 STAT. L 625.)

Vand a resident of Altoona, county of Blair,

State of Pennsylvania, have invented an Improvement in Furnaces for Heat Treatment of Armor-Piercing Projectiles, of which the following is a specification.

The invention described herein may be used by the Government, or any of its ofiicers or employees in prosecution of work for the Government, or by any other person in the United States, without payment of any royalty thereon.

YVhile our invention relates generally to furnaces, it has more particular reference to a novel construction of what are known as zone furnaces, and is more directly concerned with a zone furnace peculiarly adapted for use in the manufacture of armorpiercing projectiles.

The general object of our invention, therefore, is to provide a furnace, of the character described, for producing a shell having the maximum shock-absorbing and penetrating qualities to successfully penetrate the modern armor plate, and which will be in the best possible condition to exert its explosive value after penetration. This result 4 is obtained in our furnace by producing 'a differential temperature gradient in the shell, which, as indicated, is necessary in order to produce the most desirable structure, and to enhance the piercing property of the shell when fired against modern armor plate.

Another object is to provide a shell chamber with a novel construction of water receptacle disposed in the bottom thereof, so that the point or nose and the ogival section `of the shell may be immersed in the water in said receptacle during the annealing or drawing operations which follow the quenching operation. V

Another object is to provide a novel for'm of plug or sub-base, removably seated in said water receptacle, upon which may be supported an ordinary receptacle, containing a neutralizing medium, during heat- Ing of the shell for the quenching operation. Another object is to provide, in connection with a furnace havin@ separate combustion chambers, or heating zones, communicating through checker-work with the chamber in which the shell is suspended, a novel arrangement of burners disposed substantially tangentially to said combustion chambers, so that the gases are well difa fusedto secure uniform temperature before `reaching the shell chamber.

Another object is to provide a novel construction of checker-work between the combustion chambers and the shell chamber, so that the largest areas carrying the hot vgases will be at the surface of the shell chamber,

thereby reducing the velocity ofthe gases as they reach the shell chamber, thus reducing the impinging action thereof on the shell to a minimum.

A further object is to construct the checkerwork in such a manner as to deliver the hottest' gases to the base of the shell chamber, the heat of the gases delivered through the checker-work thence progressively decreasing until, at the top of the chamber, the smallest heat-delivery through the checker-work will be found.

A further object is to provide-a novel construction of door or cover to the open top of the shell chamber, which door or cover is in two sections, having wheels traveling on tracks supported on top of the furnace.

Another object lis to provide an extremely simple and eiiicient mechanism for suspending and rotating the shell within the shell chamber. I

The invention has for its object, finally, certain refinements and simplifications of structure and felicitous constructions, combinations and arrangements of parts, going to make up the ultimate perfection of the furnace as an entirety.

The accompanying drawings disclose an' exemplary concrete embodiment of the underlying principles of the invention, and illustrate the form which we have found best adapted for accomplishing the objects we have in View. Like reference characters 4 several views.

Fig. 4 is a sectional View on the line 4-4,

Fig. 3; V. Fig. 5 is a fragmentary View of thepupper portion of the furnace, showing, more particularly, in elevatiomthe movable cover ordoor to the open top of the lshell chamber. Fig. 6 `is a fragmentary sectional view of the upper portion of the furnace, showing, more particularly, the movable cover andthe y shell-rotating mechanism;

Fig. 7 is a fragmentary detail view, in elevation, of a portion of the shell-rotating mechanism;

Fig. 8 is a fragmentary detail view, in top plan, showing, more particularly, the shellsupporting hook and the bevel gear for rotating the same;

Fig. 9 is a detail sectional view on the line 9-9, Fig. 8; Y

Fig. 10 is a detail view, in Vcentral vertical section, of a water-receptacle, which may be disposed inthe bottom of the shell chamber; I Fig. 11 is a detail view, in side elevation, partly in section, of what we term a subbase, or plug, adapted to be disposed in the water-receptacle. Referring, now, in detail to the drawing:

The furnace wall 1 may be constructed of fire brick and incloses the central shellchamber 2, which extends from the top to the bottom of the furnace. The -furnace wall may be protected exteriorly by an insulating lining 7 inclosed by a cylindrical shell 8.

Interiorly of the furnace wall 1 are the annular, superposed combustion-chambers 3, 4 and 5, which are spaced by the horizontal separator Walls 6, ring-shaped, as shown.

Communication is established between the combustion chambers and the shell chamber 2 by means of staggered checker-work 9. This checker-work is so constructed that the smallest heat-delivery area is toward the base of the shell-chamber 2. Thence, the heat-delivery area progressively increases until, toward the top of the shell-chamber, the greatest heat-deli Very area will be foun By this construction, with sources of heat of the same intensity supplying each zone, the temperature of the gases delivered to the upper zones of the heating chamber will be less than that delivered to the bottom zone because of the distribution of such gases over a greater area.

It will also be noted that the inlet-end of the checker-ports of all zones (z'. e., the end thereof which is nearest the combustion-` chambers) is smaller than the outlet-end, or

:the .combustion chambers and pass through the upper checker ports is compensated for ajnd the heatevenly distributed throughout each Zone. v

The combustion chamber walls are tapped to provide openings 10, which Hare at their exit ends, as shown, and which communicate with burners 11. Thearrangement of the burners and the openings 10 is such that the path of travel of the gases,l as they emerge from the openings, is substantially tangential to the com'bustion-chambers.- The gases are, therefore, Well diffused, before reaching shell-chamber 2, to secure uniform temperature.

The burners 11 are, as shown, symmetrically arranged around'the furnace Wall, and a series thereof is provided for each combustion chamber, preferably six to a series, or eighteen to the furnace, all of which may be simultaneously used, or a portion thereof, may be desired.

The burnersA are preferably provided with segmental burner-plates 12, conforming in curvature to the circumferential contour of the steel jacket 8, and provided with complemental lateral flanges 18, the anges 'of one section abutting those of the adjacent section, when the burner plates are assembled, and bolts 14 passing through suchy flanges and securing the plates and consequently the burners in position with respect to the furnace. y

Each combustion chamber 3, 4 and 5 is preferably vented, at diametrically opposite points, as shown at 15, 15, to a flue 16 whichextends vertically inthe furnace wall 1 to the top thereof, to atmosphere. Each of the iues 16, 16 may be connected, at its top, if desired, to a passageway (not shown) leadingto a preheating furnace.

referably, also, ports 17 extend transversely through the lining 7 and are alined with complemental ports 18 extending transversely of the furnace wall 1 and communieating with the flues 16, 16. By preference, ports 15, 17 and 18 are in alinement, as shown. Normally. loose brick, or the like, is disposed in the openings 17, which brick may be removed, when desired.

Preferably, also, passageways 19 lead,

from the shell-chamber 2 through the checker-work 9, thefurnace wall 1, the lining 7 and the steel casing 8, whereby communication is established between the shellchamber 2 and the atmosphere. y

The bottom of the shell chamber 2 is tapered, as shown at 20, which forms a seat 4for the truncated cone-shaped bottom of a y surface 22 of the receptacle 21. The upper surface of the plug is recessed or cored, as

shown at 26, for engagement by a suitable tool in removing the plug from the receptacle 21; and the receptacle 21 is provided with recesses 25 in its inner surface, which may be engaged by a tool or tools in removing the receptacle from the furnace.

The receptacle 21 is cored transversely to provide a water-inlet port 27, which may be connected up with any suitable source of water-supply (not shown). The water-receptacle 21 is also cored to provide a plurality of longitudinal ports 28 extending from top to bottom of the receptacle, as shown, and constituting overflow channels leading to a recess 29 in the center of the bottom of the receptacle, which recess communicates with any suitable outlet (not shown). The

receptacle 21 is advantageously provided with a marginal, upstanding flangev 30, at its top, for an obvious purpose.

lt will be understood that when the furnace is used for the purpose of heating for the quenching operation, the sub-base or plug 23 is used, and an ordinary receptacle (not shown), containing some neutralizing medium to protect the point of the shell, is placed on the plug or sub-base 23, and the point of the shell is immersed in suoli neutralizing medium during-such heating operation.

When the furnace is used for the annealing or draw operations, which follow the quenching operation, the receptacle containing the neutralizing' medium and the base or plug 23 are removed from the furnace, and the shell is lowered to allow the point and part ofthe ogival portion thereof to be immersed in the water which is delivered to the receptacle 21 at a rate of ,flow which will allow the. proper temperature to be maintained in that part of the shell which is immersed.

Suitable mechanism for suspending and rotating the shell within the shell-chamber 2 is provided, and, while it is obvious suoli mechanism may take a variety of forms, that shown in the drawings is preferred and will now be described:

The open-top of the Vshell chamber 2 is adapted to be normally closed by a cover or door, which, in the embodiment shown in the drawings, is in two, complemental sect1ons 31, 31. Each of said sections is provided with wheels 32, which roll on tracks 33, 33 supported upon the top of the furnace, as shown.

Each door section carries an I-beam 34 supporting the removable bridge or bearing plate 35- carrying a bearing or leveling' portion 40 of a suspension rod 41, carryingv ai hook 42 at its lower end, by which the shell may be suspended vertically in the shell chamber 2. The upper part of the reduced portion 40 of the rod 41 is preferably threaded, as shown at 42, on which is threaded an eye-member 43.

Meshing with the gear 39 is the pinion 44 on one end of a shaft 45, which carries, at its opposite end, another gear`46 meshing with a bevel gear 47 on the end of a vertically-disposed shaft 48 connected up, through suitable intermediate mechanism, with the shaft of an electric motor.

49 designates a bracket suitably secured to the top of the furnace, as by screws 50, and provided with bearings for the rotating shaft 48.

The bracket is provided with upstanding ears 51, in which is pivoted a second bracket 52 carrying suitable bearings 53, 53, in which the shaft 45 is journaled. The bracket 52 carries a downward-inclined arm 54 at the end thereof opposite the pivotal end, which` arm is supported, at its lower end, in any suitable manner, as by resting upon one of the I-beams 34.

The complete operation involving the heattreatment of the shell in the furnace of our construction is as follows:

The shell is suspended from the hook 42 nose down, t'. e., with the nose or point thereof at the bottom of the furnace, and is heated at a rate of temperature rise consistent with good practice to a certain temperature at the nose or ogival section, by regulation of the burners in the zones or combustion chambers 3, 4 and 5, but mainly by regulation of the burners in zone 5. Any excess heat generated in the shell-chamber 2 above zone 5 will be carried through the checkerwork 9 in zones 3 and 4 to the flues 16, 16, which may be provided with damper adjustment. From the liues 16, 16, such gases may escape to the atmosphere, or they may be conveyed to a preheating furnace designed to preheat the shells prior to placing them in our furnace for the quenching heats,

i thereby utilizing the excess of hot gases not desired in obtaining the temperature gradient in the shell when heating for either the quenching or drawing heats.

rllhe gradient in the checker-work areas is desired in order to secure a slower rate of heating at the top of the furnace, due to the `volume of metal being less at these locations than at the ogival section of the shell.

shell-chamber being'of larger cross-sectional area than the ends of said ports nearest the combustion-chamber. i

2. A furnace for heating'armor-pierclng projectiles, provided with a" central shell-` chamber, with concentric superposed combustion chambers, forming separate heating zones, and with staggered checker-work between said combustion chambers and said shell-chamber, the ports through said checker-work tapering and being of progressively larger cross-sectionalarea from the outer to the inner ends thereof.

3. A vertical furnace for heating armorpiercing projectiles, provided with a central, vertical shell-chamber, with concentric superposed combustion chambers, forming lseparate heating zones, and with staggered checker-work between said combustionchambers and said shell-chamber, and extending throughout the length of the several combustion-chambers, the inner ends of the checker-work ports being of progressively small cross-sectional area from the bottom to the top of each zone. 4. A vertical furnace for heating armorpiercing projectiles, provided with a central, vertical shell-chamber, concentric, superposed combustion-chambers, forming separate heating zones, and staggeredcheckerwork between said combustion-chambers and said shell-chamber, the furnace-wall being provided with vertical flues exteriorly of saidcombustion-chambers and' with ports leading from said lues to said combustionj chambers.

5. A vertical furnace Afor heating armorpiercing projectiles, provided with a central, vertical shell-chamber, concentric, superposed combustion-chambers, forming separate heating zones, and staggered checkerwork between said combustion-chambers and said shell-chamber, the furnace-wall being provided with vertical lues exteriorly of said combustion-chambers and with perts' leading from said filles to said combustionchambers and with additional, `transverse ports extending to the circumferential exterior of the furnace.

6. A vertical furnace for heating armorpiercing projectiles, provided with a central, vertical shell-chamber, concentric, superposed combustion-chambers, forming separate heating zones, staggered checker-work between said combustion-chambers and said shell-chamber, and pipes extending transversely of the furnace from the shell-chamber to the circumferential exterior of the furnace.

7. ln a vertical furnace for heating armorplercing projectlles, provided wlth a central,

vertical shell-chamber, the combination with concentric, superposed combustion-chambers. forming separate heating zones, of staggered checker-Work between said combustion-chambers and said shell-chamber, and

pipes extending transversely of the furnace from the shell-chamber to the circumferential exterior of the furnace, the furnace-wall beingprovided with vertical tlues exteriorly of said combustion-chambers and with ports leading from said liues to said combustionchambers.

8. In a vertical furnace for heating armor-piercing projectiles, provided with a central, vertical shell-chamber, the combination with concentric, superposed combustion-chambers, forming separate heating zones, of staggered checker-work between said combustion chambers and said shellchamber, and pipes extending transversely of the furnace from the shell-chamber to the circumferential exterior of the furnace, the furnace wall being provided with vertical flues exteriorlyof said combustion-chambers and with ports leading from said iues to said combustion-chambers and with additional, transverse ports extending to the circumferential exterior of the furnace.

9. A vertical furnace for heating armorpiercing projectiles provided with a central vertical shell-chamber, superposed combustion-chambers encircling 'said shell-chamber and forming separate heating-zones, checkerwork also encircling said shell-chamber and interposed between the same and said combustion-chambers, and burners projecting into the furnace wall and communicat-` ing with said combustion-chambers and circumferentially arranged with respect to the furnace-wall.

10. A furnace for heating armor-piercing I projectiles provided with a shell-chamber, a water-receptacle removably disposed in the bottom of said shell-chamber, and a plug normally closing the top of said water-receptacle.

l1. A furnace for heating armor-piercing projectiles provided lwith a vertical shellchamber having an inclined lower portion, a Water-receptacle disposed in the bottom of said shell-chamber and having a correspondingly inclined lower portion bearing against said first mentioned inclined portion, and a plug normally closing the top of said waterreceptacle.

12. A furnace for heating armor piercing projectiles provided with a vertical shellchamber, a water receptacle disposed in the bottom of said shell-chamber and having an inner surface inclined at its top, and a plug having a correspondingly inclined` portion bearing against the inclined surface of said receptacle.

13. A furnace for heating armor-piercing projectiles provided with a vertical shellchamber, and a water-receptacle disposed in the bottom of said shellchamber and provided with a water-inlet port near its bottom and with overflow ports extending from the top to the bottom thereof.

14.-. A furnace for heating armor-piercing projectiles provided with a vertical shellchamber, and a water-receptacle disposed in the bottom of said shell-chamber and provided With a water-inlet port near its bottom, with a recess in its bottom, and with overflow ports extending from the top of said receptacle to said recess.

15. A furnace for heating armor-piercing projectiles provided with a vertical shellchamber, in combination with means for revolving a shell suspended within said shellchamber.

16. A furnace for heating armor-piercing projectiles provided with a vertical shellchamber extending to the top of the furnace, a sliding door normally covering the top of said shell-chamber, shell-suspension means supported by said door and including a sus- 1penlsion-hook, and means for revolving said 17 A furnace for heating armor-piercing projectiles provided with a vertical shellchamber extending to the top of the furnace, a sliding door normally covering the top of said shell-chamber and formed in two complemental parts, shell-suspension means supported by said door and including a suspension-hook, and means for revolving said hook.

18. A furnace for heating armor-piercing projectiles provided with a vertical shellchamber extending to the top of the furnace, tracks disposed on top of the furnace, a sliding door normally covering the top of said shell-chamber and provided with wheels running on said tracks, shell-suspension means supported by said door and including a suspension-hook, and means for revolving` said hook.

19. The method of heat treatment of armor-piercing projectiles7 which consists in subjecting said projectiles to progressively decreasing heat from the point and ogival section to the base thereof, so as to produce a differential temperature gradient in the shell.

20. The method of heat treatment of armor-piercing projectiles, which consists in suspending the shell vertically, nose down, and in impinging against said shell heated gases in different heating-zones, the heated gases impinging against the shell being of progressively decreasing intensity from the point and ogival section of the shell or projectile to the base thereof.

21. A furnace, provided with a heating chamber and combustion chambers forming separate heating zones and means for establishing communication between the combustion chambers` and the heating chamber whereby the temperature in the heating` chamber is progressively diminished from one end of the chamber toward the other.

FREDERICK C. LANGENBERG. JOHN F. FETTERLY. 

